U.S. patent application number 14/004051 was filed with the patent office on 2014-03-13 for method for reducing the absorption of nutrients through the gastrointestinal tract.
This patent application is currently assigned to GASTRO-SHAPE TECHNOLOGIES, INC. The applicant listed for this patent is Sanford Lane. Invention is credited to Sanford Lane.
Application Number | 20140074077 14/004051 |
Document ID | / |
Family ID | 46798829 |
Filed Date | 2014-03-13 |
United States Patent
Application |
20140074077 |
Kind Code |
A1 |
Lane; Sanford |
March 13, 2014 |
Method for Reducing the Absorption of Nutrients Through the
Gastrointestinal Tract
Abstract
The present invention features methods for applying a force,
such as laser or radiofrequency (RF) energy to the wall of the
small intestine, which targets and eliminates a portion of the
capillary and vascular network responsible for the transportation
of nutrients to the patient. This causes the patient to absorb a
reduced percentage of nutrients, which results in a reduced caloric
intake. Various types and shapes of applicators are used to deliver
the treatment energy, and these applicator devices are within the
scope of the present invention. The applicator can be deployed
through either a body cavity (e.g., the oral cavity), an open
surgical procedure, or a minimally invasive incision or
incisions.
Inventors: |
Lane; Sanford; (Sherborn,
MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Lane; Sanford |
Sherborn |
MA |
US |
|
|
Assignee: |
GASTRO-SHAPE TECHNOLOGIES,
INC
Geneva
CH
|
Family ID: |
46798829 |
Appl. No.: |
14/004051 |
Filed: |
March 9, 2012 |
PCT Filed: |
March 9, 2012 |
PCT NO: |
PCT/US12/28451 |
371 Date: |
November 22, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61450904 |
Mar 9, 2011 |
|
|
|
Current U.S.
Class: |
606/15 |
Current CPC
Class: |
A61B 2018/0063 20130101;
A61B 2018/00791 20130101; A61B 2018/00244 20130101; A61B 2018/00875
20130101; A61B 2018/00029 20130101; A61B 2018/00982 20130101; A61B
2018/0212 20130101; A61B 2018/00166 20130101; A61B 2018/00494
20130101; A61B 2018/00702 20130101; A61B 18/1492 20130101; A61B
18/1815 20130101; A61B 18/22 20130101; A61F 5/0076 20130101; A61B
2018/00642 20130101; A61B 18/02 20130101; A61B 18/1482 20130101;
A61B 17/22012 20130101 |
Class at
Publication: |
606/15 |
International
Class: |
A61B 18/22 20060101
A61B018/22; A61B 18/14 20060101 A61B018/14; A61F 5/00 20060101
A61F005/00 |
Claims
1. A medical device for delivering energy to the lumen of the
intestine, the device comprising: (a) an elongated housing having a
proximal end and a distal end; (b) an energy-delivery channel,
wherein the energy-delivery channel extends from the proximal end
of the housing toward the distal end; is configured to transport
energy or guide an energy conduit; and terminates beyond the distal
end of the housing in an energy-emitting element; and (c) a tissue
expander at the distal end of the housing.
2. The medical device of claim 1, wherein the elongated housing is
rigid or semi-rigid; is about 1 foot to about 25 feet long; and has
a diameter suitable for insertion through a working channel of an
endoscope or a trocar.
3. The medical device of claim 1, wherein the energy conduit
comprises an optical fiber, wire, or transducer.
4. The medical device of claim 1, wherein the energy delivery
channel or the energy conduit comprises a connector for attaching
the channel or the conduit to an energy source.
5. The medical device of claim 4, wherein the energy source is a
laser, radiofrequency generator, ultrasound generator, or cryogenic
probe.
6. The medical device of claim 1, wherein the energy-emitting
element is fixed such that energy emanates from the element in a
diffuse pattern.
7. The medical device of claim 1, wherein the energy-emitting
element is focused and moveable such that energy emanates from the
element toward a focused point, which point can vary as the element
is moved.
8. The medical device of claim 1, further comprising a second
tissue expander, wherein the first tissue expander is located
distal to the energy-emitting element and the second tissue
expander is located proximal to the energy-emitting element.
9. The medical device of claim 1 or claim 8, wherein the first
tissue expander and/or the second tissue expander is shaped as a
sphere, an ellipse, a ring, or a cone.
10. The medical device of claim 1 or claim 8, wherein the first
tissue expander and/or the second tissue expander is an inflatable
balloon.
11. The medical device of claim 1, further comprising a
visualization channel, wherein the visualization channel runs
substantially parallel to the energy-delivery channel and comprises
a scope, which is optionally moveable, attached to or integrated
with the visualization channel at or near the distal end of the
visualization channel.
12. The medical device of claim 11, wherein an optical element is
positioned over the aperture.
13. The medical device of claim 12, wherein the optical element is
a lens or filter.
14. The medical device of claim 1, further comprising a
temperature-adjustment channel, wherein the temperature-adjustment
channel runs substantially parallel to the energy-delivery channel
and is configured to transport a fluid or gas of a given
temperature to the tissue to which energy has been applied by the
device.
15. The medical device of claim 1, further comprising at or near
the distal end of the housing, a sensor for determining
temperature.
16. A method for reducing the amount of nutrients that are absorbed
into the vascular system of the small intestine of a subject, the
method comprising: providing the medical device of claim 1;
positioning the energy-emitting element of the device within the
lumen of the small intestine of the subject; and applying energy
from the device to the internal surface of the small intestine,
wherein the energy is of a type and delivered for a time sufficient
to inhibit the absorption of nutrients from the treated portion of
the small intestine.
17. The method of claim 16, wherein positioning the energy delivery
device comprises inserting the energy-emitting element of the
device into the intestine through a laproscope positioned in the
subject's abdominal cavity.
18. The method of claim 16, wherein the medical device delivers
laser energy and the method further comprises application of an
electrolyte solution between the energy-emitting element and the
surface of the intestinal tissue being treated.
19. The method of claim 16, wherein the medical device delivers
laser energy and comprises or is connected to a power source
supplying energy with a power of about 0.1 to about 50
watts/cm.sup.2.
20. The method of claim 19, wherein the power is at least or about
25, 30, 35 or 40 watts/cm.sup.2.
21.-37. (canceled)
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of the priority date of
U.S. provisional application No. 61/450,904, which was filed Mar.
9, 2011. For any U.S. patent or application that claims priority to
the present application, the content of this earlier filed
provisional application is hereby incorporated by reference herein
in its entirety.
FIELD OF THE INVENTION
[0002] The present invention features medical devices, kits and
methods for reducing the absorption of nutrients through the
gastrointestinal tract by applying energy, for example a
radiofrequency signal or laser, to the wall of the small intestine.
The methods can be used to help maintain an individual's weight or
to treat overweight or obese individuals.
BACKGROUND
[0003] The percentage of the world's population suffering from
obesity or morbid obesity is steadily increasing. It is well
established that obese people are susceptible to increased risk of
serious medical conditions, including heart disease, stroke,
diabetes, and pulmonary disease, and even mild obesity increases
these risks. There are also difficult social and societal
implications, and overweight people are more prone to accidental
injury. Because obesity affects a patient's life so greatly, many
methods of treatment are being used and many others are being
researched. For some patients, dietary modification alone can lead
to successful weight loss but achieving or maintaining a consistent
and healthy weight remains difficult for many people.
[0004] Many types of non-operative therapies for obesity are
available, but these therapies rarely result in permanent weight
loss and, in some cases, produce unwanted side effects or
complications for the patient. These therapies include dietary
counseling, hypnosis, behavior modification, and pharmacological
intervention. In other instances, mechanical devices are inserted
into the body through nonsurgical means. For example, gastric
balloons can be used to fill the stomach. Such devices, however,
cannot be deployed over a long period of time as they can cause
irritation, including ulcerations, which necessitates their
periodic removal. This causes temporary or permanent interruption
of treatment. For reasons such as these, the medical community has
adopted more aggressive surgical approaches, particularly for
treatment of morbid obesity.
[0005] Many surgical procedures for treating morbid obesity are
directed toward the prevention of normal absorption of food
(malabsorption) and/or a restriction of the stomach to make the
patient feel full sooner (gastric restrictions). A common technique
is gastric bypass surgery. In variations of this technique, the
stomach is divided into two isolated pouches, with the upper pouch
having a reduced food capacity. The upper pouch is then connected
to the jejunum through a small stoma. This reduces the size of the
stomach, reduces the extent to which food can be processed in the
stomach, and reduces absorption from the intestine (by bypassing
the duodenum). Other procedures remove portions of the small
intestine or shunt segments of the small intestine to reduce the
amount of nutrients absorbed into the body. These procedures are
considered major surgery, as they constitute extensive and
permanent reconstruction of the gastrointestinal (GI) tract, and
they carry with them all of the operative and postoperative
complications and risks of open abdominal surgery.
[0006] One procedure, gastric banding, involves the placement of a
polymer or metallic band around a portion of the GI tract. The band
can be sized and positioned to constrict flow to or within the
stomach or other parts of the GI tract, and the extent of the
constriction can vary depending on a given patient's condition.
However, in each case the band remains as an implanted device, and
the surgeon may also implant a separate device that is connected to
the band and capable of adjusting it. Typically, gastric banding is
performed in an open surgical environment. There are minimally
invasive techniques, but these can be problematic. Another
disadvantage of gastric banding is that the patients are reluctant
to undergo procedures in which a device is left in the body.
SUMMARY
[0007] The present invention is based, in part, on our discovery of
a minimally invasive, non-mechanical means for reducing nutrient
absorption into the body through the gastrointestinal (GI) tract.
Unlike existing methods such as gastric bypass and gastric banding,
which result in significant physical or mechanical alterations of
anatomical structures and pathways, the present methods inhibit
nutrient absorption into the body, thereby reducing caloric
consumption and promoting weight loss or weight maintenance,
without reconstruction of the GI tract or attachment of mechanical
appliances.
[0008] In one aspect, the invention features medical devices for
delivering energy to the lumen of the intestine. The devices
include: (a) an elongated housing having a proximal end and a
distal end; (b) an energy-delivery channel; and (c) a tissue
expander at the distal end of the housing. The energy-delivery
channel can: extend from the proximal end of the housing toward the
distal end; be configured to transport energy or guide an energy
conduit; and terminate beyond the distal end of the housing in an
energy-emitting element (that is, the energy-delivery channel and
the energy-emitting element are operably linked).
[0009] As will be apparent to one of ordinary skill in the art, the
terms "proximal" and "distal" are relative terms, signifying the
location of one element relative to another. "Proximal" refers to
the portion of an item (e.g., a device as a whole; a housing
therefor, or a channel running through the device) that is nearest
the operator (e.g., a physician). "Distal" refers to the portion of
the item that is furthest from the operator. "Proximal" and
"distal" may even be used to designate the relative positions of
two elements within the same end of an item. For example, we
describe devices that include, at their distal end, two tissue
expanders. Even though both are found at the distal end of the
device, the tissue expander that is nearest the operator is the
proximal tissue expander and the tissue expander that is furthest
from the operator is the distal tissue expander. An element that is
said to be located in the distal region of an item or at a distal
end, may or may not be the most distal element of the item.
[0010] The elongated housing can be rigid or semi-rigid. It can
vary in length from about 1 foot to about 25 feet, and it can have
a diameter suitable for insertion through a working channel of an
endoscope or a trocar.
[0011] The energy conduit can include an optical fiber, wire, or
transducer, and the energy delivery channel or the energy conduit
can include a connector for attaching the channel or the conduit to
an energy source (e.g., a laser, radiofrequency generator,
ultrasound generator, or cryogenic probe). The energy-emitting
element can be fixed such that energy emanates from the element in
a diffuse pattern. Alternatively, the energy-emitting element can
be focused and/or moveable such that energy emanates from the
element toward a focused point, which point can vary depending on
how the element is focused and/or how the element is moved.
"Diffuse" can mean completely isotropic radiation or directional
radiation that has a strong peak intensity in one direction and
some relatively small portion (side lobes) emanating in various
other directions (a common energy distribution in radiofrequency
beams). The latter is generally considered a focused beam. Thus,
the energy-emitting element can produce a focused beam with side
lobes.
[0012] Any of the devices described herein can include a plurality
of tissue expanders. For example, a device can include first and
second tissue expanders. The first tissue expander can be located
distal to the energy-emitting element, and the second tissue
expander can be located proximal to the energy-emitting element.
Either or both of the first and second tissue expanders can be
shaped as a sphere, an ellipse, a ring, or a cone; either or both
can be inflatable (e.g., an inflatable balloon).
[0013] Any of the devices described herein can include a
visualization channel, which may run substantially parallel to the
energy-delivery channel and include a scope, which is optionally
moveable, attached to or integrated with the visualization channel
at or near the distal end of the visualization channel. An optical
element, such as a lens or filter, can be positioned over the
aperture.
[0014] Any of the devices described herein can include a working
channel, which may be used to administer electrolytes to the
intestinal lumen, to insert surgical instruments that may
facilitate manipulation of the tissue, or to apply a material (a
fluid or gas) that can modulate (e.g., reduce) the temperature of
the tissue during treatment. The working channel can run
substantially parallel to the energy-delivery channel and can be
configured to transport a fluid or gas of a given temperature to
the tissue to which energy has been applied by the device.
[0015] Any of the devices described herein can include, preferably
near the distal end of the housing and/or near the tissue targeted
for treatment, a sensor for determining a physiological parameter,
such as temperature.
[0016] In another aspect, the invention features kits that include
a device as described herein and instructions for use. The kits can
further, optionally, include materials to facilitate the assembly,
disassembly, or sterilization of the devices.
[0017] In another aspect, the invention features methods of
reducing the amount of nutrients that are absorbed into the
vascular system of the small intestine of a subject. The methods
can be carried out by providing a device as described herein;
positioning the energy-emitting element of the device within the
lumen of the small intestine of the subject; and applying energy
from the device to the internal surface of the small intestine. The
energy is of a type and delivered for a time sufficient to inhibit
the absorption of nutrients from the treated portion of the small
intestine. Positioning the energy delivery device can be
accomplished by inserting the energy-emitting element of the device
into the intestine through a laparoscope positioned in the
subject's abdominal cavity or an endoscope positioned in the
subject's upper GI tract. The medical device can deliver laser
energy, and the method can further include application of an
electrolyte solution between the energy-emitting element and the
surface of the intestinal tissue being treated. A device can be
connected to a power source supplying energy with a power of about
0.1 to about 50 watts/cm.sup.2 (e.g., power of at least or about
25, 30, 35 or 40 watts/cm.sup.2). Where the medical device delivers
laser energy, it can include or be connected to a power source
supplying energy with a pulse width of about 1 ms to about 10 sec
(e.g., at least or about 0.01, 0.5, 1.0, 1.5, or 2.0 sec). Where
the medical device delivers laser energy, it can include or be
connected to a power source supplying energy with a pulse
configuration of about 1 pps to about 1,000 pps and, in some
embodiments up to about 10,000 pps with a reduction in pulse width.
Where the medical device delivers radiofrequency energy, it can
include or be connected to a power source supplying energy with a
power of about 1 to about 100 watts/cm.sup.2 (e.g., about 25, 30,
35 or 40 watts/cm.sup.2). Where the medical device delivers
radiofrequency energy, it can include or be connected to a power
source supplying energy with a pulse width of about 1 ms to about
10 sec (e.g., at least or about 0.1, 0.5, 1.0, 1.5, or 2.0 sec).
Where the energy delivery device delivers radiofrequency energy, it
can include or be connected to a power source supplying energy with
a pulse configuration of about 1 pps to about 1,000 pps.
[0018] The treatment can be "semi-permanent" in that the
vasculature in the subject may return to the absorption capacity it
had prior to treatment over the course of about six to twelve
weeks. The methods may reduce the percentage of the nutrients in
the small intestine that are absorbed into the vascular network of
the small intestine, thereby reducing the subject's caloric
intake.
[0019] The subject can be a mammal (e.g., a human).
[0020] The methods can further include the step of collecting,
through a sensor placed adjacent to the treated tissue, data that
provides feedback useful in determining whether the amount of
energy supplied to the tissue is sufficient. The data can be
obtained by visualization, impedance, ultrasound, or temperature
measurement, which may be obtained by a device located outside of
or separate from the medical device. The data can be obtained
periodically throughout the treatment method.
[0021] While the invention is not limited to methods and devices
that achieve reduced caloric absorption by any particular
physiological mechanism, the expectation is that blood flow within
the treated intestinal tissue (e.g., the tissue responsible for
absorption of nutrients) is impaired. For example the applied
energy may seal, collapse, narrow, and/or eliminate a portion of
the vascular and lymphatic structures.
[0022] The energy input can vary so long as it produces the desired
outcome of reduced caloric absorption. For example, the energy
input can be configured as an electrosurgical signal or a laser,
and the energy applied to the target tissue (including, for
example, lymphatic ducts, capillaries, other blood vessels, and
blood) affects the tissue and/or blood, resulting in reduced
nutrient absorption. For example, the treatment can result in about
a 10-20% reduction in caloric absorption immediately after
treatment relative to absorption before treatment or to absorption
from an untreated intestine. The temperature can be monitored
(e.g., with a thermal sensor) and the effects of energy absorption
can also be monitored (e.g. by a visual inspection as the procedure
is being carried out). While the energy may be delivered in the
context of conventional surgery, where the intestine is accessed
through a conventional incision, an advantage of the present method
is that the energy emitting portion of a device (e.g., a transducer
at an applicator tip or fiber-optic) can be guided to the intestine
through a mechanical guide placed through a smaller incision (e.g.,
the guide can be a conventional device used in surgery, such as a
catheter, trocar, or laparoscope). In such circumstances, the
incision can be minimized. Treatment through the abdominal wall may
be preferred where the stomach has been surgically reconfigured. In
many instances, however, the energy can be applied by way of a
device inserted through the oral cavity (e.g., within a channel of
an endoscope).
[0023] The type of energy applied can vary, as described further
below. For example, devices useful in the present methods include
those that emit electromagnetic energy. More specifically, the
emitted energy can be radiofrequency energy (e.g., where the
energy-emitting element of the device comprises an electrode or
array of electrodes for transmission of radio frequency electrical
current), microwaves (e.g., where the energy-emitting element
comprises a microwave antenna), light or laser energy (e.g., where
the energy-emitting portion of the device comprises an optical
waveguide or optical fiber) or sound energy (e.g., ultrasound).
However, in all cases, the energy, when applied to tissue in the
intestinal tract, permanently or semi-permanently reduces caloric
uptake; the functionality of the treated vessels, with respect to
the absorption of nutrients and calories, is reduced. Laser
treatment may be advantageous because laser energy at certain
wavelengths will pass through the mucosal lining without damaging
it and be absorbed by underlying structures, such as blood vessels
and lymphatic ducts.
[0024] The amount of tissue affected and the degree to which any
tissue within a treatment area is affected can vary depending on
the extent of the treatment. For example, the treatment may be
applied to only about 4-6 inches along the length of the intestine
(e.g., within the duodenum). Where more aggressive treatment is
required, the treatment can be applied to a greater length, for
example, about 10-15 inches along the length of the intestine
(e.g., of the duodenum). The degree to which any tissue within a
treatment area is affected can also vary by varying the amount of
energy applied and/or the length of the treatment. The more tissue
that is treated and the more intense the treatment, the greater the
reduction in the absorption of nutrients and calories. For example,
the extent of the treatment will depend on the energy configuration
(i.e., the power applied, the time, the phase, and the
configuration of any pulsed energy (e.g., the frequency, amplitude,
and the pulse). The proximal portion of the duodenal lining is
initially smooth, but as the duodenum moves further from the
stomach, the lining acquires folds and mall projections (villi and
microvilli). The villi and microvilli increase the surface area of
the duodenal lining, allowing for greater absorption of
nutrients.
[0025] Although the methods of the invention can be directed to the
duodenum, the remainder of the small intestine, including the
jejunum and the ileum, can also be treated. These sections of the
small intestine also absorb fats and other nutrients. The
intestinal wall is supplied with blood vessels that carry the
absorbed nutrients to the liver through the portal vein. Small
amounts of enzymes that digest proteins, sugars, and fats are also
released along with mucus and water, which lubricates the
intestinal contents, which helps dissolve the digested fragments.
All of these factors contribute to the process of digestion, which
ultimately leads to the absorption of nutrients by the vascular
system. While the invention is not so limited, we expect treatment
of the small intestine to be effective when the duodenum is
targeted because this region both absorbs fats and also sends
signals to the more distal regions of the small intestine to
facilitate further absorption. Thus, targeting the duodenum
directly inhibits absorption from that region of the intestine and
may also indirectly inhibit absorption from the ileum and/or
jejunum.
[0026] As noted, the present devices are either introduced through
a body cavity (e.g., the oral cavity) or are inserted directly into
the small intestine through an abdominal incision. The devices can
be configured so the energy emitting portion of the device is
simply passed along a length of undisturbed intestinal lumen, in
which case energy primarily reaches the peaks of the folds
containing vascular and lymphatic structures, or passed along a
length that has been expanded, in which case energy reaches an
increased percentage of vascular and lymphatic structures during a
procedure. In some cases, the small intestine will be treated
through the entire length with a low percentage of vessels and
ducts affected. In other cases, small sections of the small
intestine may be treated using a larger applicator resulting in a
greater percentage of vasculature and lymphatic treatment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 illustrates a medical device for treating tissue
within the small intestine. The device has a single tissue expander
at the distal end with a smooth, conical exterior and four internal
channels (for inflation of the tissue expander, energy delivery,
visualization, and a working channel for electrolyte, coolant, or
vacuum application).
[0028] FIG. 2 illustrates a medical device for treating tissue
within the small intestine. The device has a single tissue expander
at the distal end in the shape of an elongated balloon and four
internal channels.
[0029] FIG. 3 illustrates a medical device for treating tissue
within the small intestine. In this device, the energy-emitting
element lies between a first tissue expander at the distal tip and
a second tissue expander, which is also in the distal region (but
more proximal to the operator). The tissue expanders are shaped
differently, illustrating the heterogeneity of this element.
[0030] FIG. 4 illustrates a medical device for treating tissue
within the small intestine. In this device, the energy-emitting
element lies between a first tissue expander at the distal tip and
a second tissue expander, which is also in the distal region of the
device but more proximal to the operator. The tissue expanders in
this embodiment are similarly shaped.
[0031] FIG. 5 illustrates a pair of medical devices for treating
tissue within the small intestine. In the uppermost device (5A),
the energy-emitting element is positioned between two differently
shaped tissue expanders (the more proximal of the two being
spherical). In the lower-most device (5B), both of the tissue
expanders are spherical. Where the energy-emitting element is fixed
and energy emission is unrestricted in direction, energy can
emanate equally well in any or all directions from its point of
origin (5C). Where the energy-emitting element is focused and
moveable, energy emanates toward a focused point and can move or
"sweep" around the intestinal lumen (5D).
[0032] FIG. 6 illustrates a medical device for treating tissue
within the small intestine. The energy-emitting element is an
active electrode band encircling or recessed within a spherical
tissue expander. A device configured in this manner can be used for
radiofrequency application of energy. The active electrode band
serves as the active electrode for monopolar energy application.
For bipolar energy, the spherical tissue expander can provide a
return energy path. The spherical tissue expander can be
transparent to facilitate viewing and illuminating the tissue.
[0033] FIG. 7 illustrates a control system for energy application
to a subject with a device as described herein.
DETAILED DESCRIPTION
[0034] The present invention provides compositions (i.e., devices
and kits) and methods for applying energy to the small intestine
(e.g., the internal, lumenal surface of the duodenum, ileum, and/or
jejunum) to reduce the ability of that tissue to absorb calories
from food. Although the invention is not limited by the
physiological mechanisms underlying the reduction in caloric
uptake, we expect that the present devices and methods impair blood
vessels and lymphatic tissue in the treated areas, thereby reducing
absorption of nutrients and reducing, in effect, the treated
patient's caloric intake. Again, while the invention is not so
limited, we hypothesize that the devices and treatments will not
interrupt or impair the secretion of mucus, bile, or pancreatic
enzymes, or their mixture with water to any significant or
detrimental extent (allowing the bowel to function essentially
normally). However, nutrients within a mixture of these fluids and
digested food will be absorbed into the vascular system in a
treated patient at a rate less than the normal rate of absorption
(i.e., the rate in an untreated individual) and/or in an amount
less than the normal amount absorbed.
[0035] Referring to the figures, FIG. 1 illustrates a device 10 for
applying energy to tissue within the intestinal lumen. The
energy-application device 10 generally includes a housing 12,
having a proximal end 14 and a distal end 16. Energy is shown
emanating from the energy-emitting element 18 as energy from an
energy source travels through the energy-delivery channel 20 from
the proximal end 14 to the distal end 16 of the housing 12. The
embodiment of the device 10 that is illustrated also includes a
visualization channel 21, which terminates in a scope 22; a working
channel 23, which terminates in a dispensing port 24; and an
inflation channel 26, which terminates in a tissue expander 28. A
sensor 30 is present at one or more points on the circumference of
the tissue expander 28 to collect data, such as temperature, from
the treatment environment. The energy-emitting element 18, the
tissue expander 28, and any one or more of the visualization
channel 21, scope 22, working channel 23, dispensing port 24,
inflation channel 26, and tissue expander 28 may be fixed relative
to one another and/or relative to the housing 12. Alternatively,
the energy-emitting element 18, the tissue expander 28, and any one
or more of the visualization channel 21, scope 22, working channel
23, dispensing port 24, inflation channel 26, and tissue expander
28 may be flexible, malleable, or flexibly or malleably
interconnected so as to permit adjustment of their relative
orientation or position relative to one another and/or relative to
the housing 12. Preferably, the housing 12 is relatively rigid or
semi-rigid (at least rigid enough to be advanced through an
endoscope and the intestinal lumen).
[0036] A scope 22 is attached to or integrated with the
visualization channel 21 at or near the distal end 16. Scope 22
collects imagery from within the intestinal lumen via an aperture,
which imagery may then be output on a monitor or display. The
imagery can provide visual confirmation of both the anatomical
surroundings and the relative orientation of device 10. The
physician can thus utilize the imagery as a visual aid in properly
positioning the energy-emitting element 18.
[0037] In some embodiments, the scope 22 is a component of a fiber
optic-based system that transmits images over an optical fiber
within the visualization channel 21 to a display device (not
shown). It should be understood, however, that other scopes,
including ultrasound and infrared sensors, are useful and can be
incorporated into device 10. The term "scope" is used herein to
encompass all image capture devices, visualization devices,
cameras, sensors, and any other element that captures and can
transmit images, so long as the element is suitable (for example,
in size and content) for surgical use.
[0038] While the position of the visualization channel 21 can vary,
it may be preferable to position the visualization channel 21 such
that the scope 22 is relatively unobstructed by any other element
of the device 10 and such that the scope 22 can be rotated or
otherwise adjusted to obtain images from a variety of field. For
example, scope 22 can be rotated about the axis of the
visualization channel 21 as a periscope is rotated.
[0039] Visualization of the intestinal lumen will be aided by a
light source. Light may be provided by a light source on the
present device or a light source on or inserted through an
endoscope or similar surgical device through which the present
device has been inserted.
[0040] One of ordinary skill in the art will understand that many
if not all of the features and elements described in the context of
FIG. 1 can be variously incorporated in other embodiments of the
present device.
[0041] Referring to FIG. 2, device 10 may include a connector 32 at
proximal end 14. Connector 32 may be configured to couple device 10
to a vacuum source (through which negative pressure may be applied
to a subject's tissue and/or the intestinal lumen through working
channel 24), a fluid delivery source and mechanism (through which
an electrolyte solution or coolant may be applied to a subject's
tissue through working channel 24), a control system, a power
source, a data collection system, and the like, and any combination
thereof. A handle may be attached that includes actuators or other
control mechanisms for any of the systems, power sources, energy
sources, or other sources to which device 10 is coupled via
connector 26 (e.g., a switch to activate or deactivate energy,
fluids, or coolant delivery to a subject's tissues). Devices
including one or more handles and/or switches for regulating the
delivery of energy or matter (e.g., an electrolyte solution) to
device 10 are within the scope of the present invention.
[0042] In the embodiment of the device 10 that is illustrated in
FIG. 2, energy is shown emanating from the energy-emitting element
18 as energy from an energy source travels through the
energy-delivery channel 20 from the proximal end 14 to the distal
end 16 of the housing 12. The energy-delivery channel 20 in this
embodiment guides an energy conduit 34. The "conduit" is to be
understood as broadly encompassing any material that facilitates
the flow of energy from a source to the energy-emitting element 18
(e.g., an optical fiber). In this embodiment, the device 10 also
includes a visualization channel 21, which terminates in a scope
22; a working channel 23, which terminates in a dispensing port 24;
and an inflation channel 26, which terminates in a tissue expander
28. The sensor 30 is positioned between the energy-emitting element
and the tissue expander 28. Information detected by the sensor 30
can be conveyed through the working channel 23 or otherwise
transmitted to a control system or to the physician. Any of these
elements can be fixed relative to one another and/or relative to
the housing 12. Any one or more of these elements can be flexible,
malleable, or flexibly or malleably interconnected. The tissue
expander 28 at the distal end 16 is oblong or elongated in shape
and may be rigid or expandable (e.g., inflatable).
[0043] Referring to FIG. 3, an embodiment is illustrated in which
the device 10 includes a first and a second tissue expander 28 and
28' on either side of the energy-emitting element 18. The first and
second tissue expanders 28 and 28' assume different shapes.
Embodiments in which the energy-emitting element lies between two
tissue expanders may be preferable where more aggressive treatment
is desired, as stretching the tissue on both sides of the
energy-emitting element should expose a greater amount of the
tissue to the emitted energy.
[0044] Referring to FIG. 4, an embodiment is illustrated in which
the device 10 includes a first and a second tissue expander 28 and
28' on either side of the energy-emitting element 18. The first and
second tissue expanders 28 and 28' are highly similar in size and
shape. As noted, one may configure the energy-emitting element
between two tissue expanders when more aggressive treatment is
desired.
[0045] Referring to FIG. 5, an embodiment is illustrated in which
the device 10 carries an energy-emitting element 18 positioned
between two differently shaped tissue expanders 28 and 28', the
more proximal of which 28' is spherical (5A) and extends well away
from the central axis 36. In another embodiment, the tissue
expanders 28 and 28' are both spherical and may be inflatable.
Where the energy-emitting element 18 is fixed and energy emission
is unrestricted in direction (e.g., unshielded), energy can emanate
equally well around the central axis 36 (as illustrated in FIG.
5C). Where the energy-emitting element 18 is focused, shielded,
and/or moveable (e.g., rotatable around the central axis 36),
energy emanates toward a focused point 38 and can move or "sweep"
around the intestinal lumen (as illustrated in FIG. 5D). The energy
(e.g., laser energy) can be projected directionally over a narrow
arc (e.g., 30-60 degrees) or over all points of the arc (i.e.,
around) 360.degree.. By way of analogy, the energy-emitting element
illustrated by FIG. 5C is akin to a simple light bulb whereas the
energy-emitting element illustrated by FIG. 5D is akin to a
flashlight.
[0046] Referring to FIG. 6, an embodiment is illustrated in which
the energy-emitting element 18 circumscribes or is integrated
around the periphery of a tissue expander 28. The remaining
elements of the device can be selected from those described
herein.
[0047] Referring to FIG. 7, a system as described herein is
illustrated which encompasses a control system and power source 40
operably linked via a conveyor 42 (e.g., wires, cables, or other
conduits) to a proximal region 14 of the device and, optionally, to
the connector 32. The device 10 optionally includes one or more
handles or switches accessible to the physician in the region of,
or extending from, the conveyor 42, connector 32, or proximal
region 14 of the device 10, and these handles or switches (or the
like) can be used to modulate the application of energy based on
feedback received by the physician. Alternatively, the modulation
can be automated by virtue of a connection between a feedback
conveyor 44, conveying information from a sensor, as described
herein, and the control system 40.
[0048] The positioning of the devices within a subject can be
facilitated by insertion through an elongated, semi-ridged,
flexible, and/or steerable fiber delivery system. Tissue expanders
could be partially inflated prior to insertion into the small
intestine as desired. Inflatable tissue expanders can be
advantageous in that they can be inflated to various degrees,
allowing the surgeon to customize the amount of the vascular system
to be treated by adjusting the amount of expansion (greater
inflation/expansion would expose a greater percentage of the
intestinal wall for treatment). Once the energy-emitting element
reaches the area to be treated, the tissue expander would then be
expanded to the desired amount, and energy would be applied for a
time sufficient to reduce the vascularization of the tissue to an
extent that reduces nutrient uptake. The tissue expander can then
be contracted (e.g., deflated) and moved to a new, untreated area
where it would be re-expanded (e.g., re-inflated) prior to
treatment of the new area.
[0049] Where the energy-emitting element is integral to a tissue
expander, the material used for the tissue expander is preferably
transparent to the emitted energy. For example, a laser with a
wavelength of 577 nm could be used due to its high level of
absorption into the blood vessels, and a material (e.g., a resin or
polymer, such as plastic) can be used in the tissue expander that
would not absorb the 577 nm laser light, allowing the energy to
reach the target vasculature. This selectivity would also help
prevent the laser from being absorbed into normal structural or
connective tissue of the intestinal wall.
[0050] Where the tissue expander is at the far distal end (the tip)
of the device, they may be referred to as an applicator tip,
particularly where a circumferentially located ring electrode (for
use with radiofrequency energy) is used as an energy-emitting
element. The ring electrode could have an equatorial location in a
spherical tissue expander to allow the electrode to rest directly
against the intestinal wall at the point of treatment. This style
tip can be used when the energy source is either a monopolar or
bipolar radiofrequency energy source. If bipolar energy is used,
the device can include a fine insulator between an equatorial
electrode and each of the half sphere ends of the ball. Although a
tip configured in this manner could be expandable, using a fixed
size applicator may have advantages. For example, a fixed size
applicator can be advanced through the intestine with the energy
source on, and this could increase the speed of the treatment.
[0051] For the sake of clarity and labeling in the illustrations,
the various channels within the present devices are not typically
drawn to their full length (with the proximal ends generally
staggered to aid identification). It will be clear from this
description and one of ordinary skill in the art would understand
that the channels generally traverse the entire longitudinal axis
of the housing, operably connecting the proximal and distal ends of
the devices.
[0052] The present invention can be used to treat subjects who are
overweight or obese, including subjects who have tried and failed
to lose weight by dieting and other behavioral modifications. A
person who is overweight or obese is at risk for a number of health
related issues, such as diabetes, atherosclerosis, coronary artery
disease, myocardial infarction, hypertension, congestive heart
failure, arthritis, sleep apnea, dyslipidemia, lipodystrophy, and
cardiovascular accident. Thus, while we have characterized the
devices and methods of the invention as devices and methods for
promoting weight loss, they are useful in reducing the risk of many
undesirable conditions associated with, or secondary to, excess
body weight (including those listed above). Typically, a subject is
considered overweight if his or her weight is at least or about 10%
higher than a healthy norm (i.e., the top of a range considered to
be a healthy norm), as defined by standardized height/weight
charts, and considered obese if his or her weight is at least or
about 30% or more above what is considered to be a healthy weight.
Thus, subjects meeting these standards are candidates for treatment
as described herein, unless there is a prevailing counterargument.
One of ordinary skill in the art is able to determine whether or
not a given subject is a good or poor candidate for treatment, and
identifying a patient in need of treatment (e.g., by assessing
height, weight, BMI, and other measurements) can be a step included
in the present methods. While the methods of the invention can be
applied to any mammal in need of treatment, the subjects will
likely be human in the vast majority of cases. However, since the
methods are minimally invasive and relatively inexpensive,
veterinary application to animals such as domestic pets (e.g., cats
and dogs) is also feasible. In recent years, the incidence of
obesity has become more prevalent in people of all ages, including
children and the elderly. The subjects amenable to treatment with
the present methods may vary greatly in age and include children,
teens, adults, and elderly men and women. Here again, the minimally
invasive nature of the methods is an advantage. The present devices
can readily be proportioned (e.g., in length and diameter) to
accommodate any type of subject (e.g., a human child or adolescent,
or a domesticated animal).
[0053] As is well known in the art, the small intestine is located
in the abdominal cavity below the diaphragm and is positioned in
the GI tract between the stomach and the large intestine. The small
intestine is used for digestion of food and for mixing food with
gastric juices to facilitate its breakdown. The stomach releases
food into the duodenum (chyme), the first segment of the small
intestine. Food enters the duodenum through the pyloric sphincter
in amounts that the small intestine can digest. When full, the
duodenum signals the stomach to stop emptying or transferring food.
The duodenum receives pancreatic enzymes from the pancreas and bile
from the liver and gallbladder. These fluids, which enter the
duodenum through an opening called the sphincter of Oddi, are
important in aiding digestion and absorption. When energy is
applied to the duodenum, as described herein, this sphincter can be
avoided. Peristalsis also aids digestion and absorption by churning
up food and mixing it with intestinal secretions.
[0054] While the first few inches of the duodenal lining are
smooth, the remainder of the lining has folds, small projections
(villi), and even smaller projections (microvilli). These villi and
microvilli increase the surface area of the duodenal lining,
allowing for greater absorption of nutrients. The remainder of the
small intestine, located below the duodenum, consists of the
jejunum followed by the ileum. Turning movements facilitate
absorption. Absorption is also enhanced by the vast surface area
made up of folds, villi, and microvilli. As noted, the present
methods can be applied to any area of the small intestine, although
the duodenum may be favored.
[0055] The wall of the small intestine is anatomically divided into
four layers. The mucosa is a membrane that lines the inside of the
digestive tract. Materials in broken down food cross the mucosa to
reach the bloodstream and are carried off to other parts of the
body for storage or for chemical change. Although this process
varies with different types of nutrients, all nutrients ultimately
enter the body through vascular structures. Therefore, energy
emitted by the present devices and delivered by the present methods
can be delivered to any layer of the intestine that contains
vascular structures that absorb nutrients and calories. For
example, the energy-emitting element can be positioned on or near
the surface of the inner layer and it may be configured such that
emitted energy penetrates the mucosa and is delivered to the
underlying vascular structures. For example, in the case of a laser
delivery system, the wavelength of emitted light may be set such
that it penetrates the mucosa and is absorbed by the vascular
and/or lymphoid structures (e.g., laser energy in the 480 nm to 650
nm range is absorbed by the target chromophore while passing
through the mucosa). The emitted energy may target blood within the
vessels, the walls of the vascular structure, lymphatic ducts, or a
combination of these tissue types.
[0056] FIGS. 1-5 illustrate devices in which a tissue expander lies
distal to the energy-emitting element of the device, and FIG. 6
illustrates a device in which the tissue expander incorporates the
energy-emitting element. In other embodiments, the tissue expander
may be located only proximal to the energy-emitting element. In any
configuration, the energy-emitting portion of the device may also
include an element for additional diffusion of the emitted energy
(an element that enhances a diffuse pattern) or a shield that
preferentially directs the emitted energy to a more focused point
on the tissue. In any embodiment, the energy-emitting element may
be preceded and/or followed by a shaped tissue expander, which can
be a spherical, elliptical, or elongated structure of either a
fixed size and shape or an adjustable size and shape (e.g.,
inflatable). For example, the tissue expander(s) can be sized or
adjusted in size to have a dimension (e.g., a cross-sectional
diameter) about the size of the intestinal lumen or slightly larger
to achieve the tissue expansion described herein; a tissue expander
can distend the lumen so that more tissue is exposed to the emitted
energy and/or the tissue is more evenly treated. When present, a
shield around a portion of the energy-emitting element directs the
emitted energy and can be used to achieve either a random or a
specific treatment pattern. For example, the focusing element can
rotate the energy source such that a beam of energy is rotated
360.degree. around a central axis. If heat is used to treat the
tissue, a heat source (e.g., a fiber-optic) may terminate in a
metallic device that will distribute the heat energy that it
absorbs. Spatially, the distribution can be uneven or substantially
even. The metallic portion of the device or other heat diffusor can
be designed as a cylindrical or spherical device that is moved or
rolled against the intestinal wall. It may also be fashioned as a
semi-circular or cap-type structure. The metallic element may be
made of aluminum, stainless steel, silver, gold or any other
electrically conductive material. The material may be an alloy
(e.g., stainless steel), and one or more of the materials,
including those just listed can be mixed or used in combination to
form the applicator portion of a device. Alternatively,
nonconductive material such as carbon fiber, fiberglass, or plastic
may be used. If metallization is performed on the carbon fiber,
fiberglass, or plastic, it may be continuous or may alternate with
aluminum or other conductive mesh or wires. Further, the
energy-emitting portion of the device may be rigid, semi-rigid or
more substantially flexible. Moreover, the element may be solid or
hollow. For example, electrodes may be passed through a hollow wire
to a metalized tip for application to the tissue.
[0057] Once the desired amount of effect is obtained, the energy
may be interrupted (i.e., terminated for a time). Depending on the
exact configuration of the energy-applicator device, all or a
portion of the device may be removed from its location near the
treated tissue and redeployed to another area of the small
intestine. For example, either the device as a whole or a potion
thereof (e.g., the energy-emitting element) may be withdrawn,
withdrawn and then moved to a new area, or simply advanced to a new
area. During this process, visualization can be maintained through
a viewing port and visualization channel contained either within
the device or within a laparoscope, flexible catheter, or
endoscope, through which the device has been inserted (e.g.,
through the esophagus, stomach, and into the small intestine).
[0058] As noted, the device can be deployed through either an open
surgical procedure, through one or more minimal incisions, or
through a body orifice, such as the mouth. In the case of an oral
entry, a flexible scope carrying the device, optionally with its
visualization, illumination, and temperature-adjustment channel(s)
and sensor elements, can enter through the esophagus, passing
through the stomach and into the small intestine. The flexible
(i.e., non-rigid) scope could then be gradually moved through the
small intestine treating the desired area(s), with the present
device deployed from therein. The device can also be brought into
contact with the small intestine through the rectum. Alternatively,
it may be desirable to use a trocar to enter the abdominal cavity.
A flexible scope would then be advanced to the beginning or some
more distal portion of the small intestine where an incision would
be made allowing the scope to be advanced directly into the small
intestine. In one treatment procedure, a trocar is used to create
an incision point in the abdominal wall. An instrument such as a
laparoscope is then inserted and advanced to a region of the small
intestine (e.g., the proximal section). Using standard surgical
instruments an incision is then made into the small intestine
providing direct access to the lumen of the small intestine. Once
access into the small intestine is gained, the applicator can then
be advanced into the small intestine and positioned in any part of
the small intestine for treatment using one of the methods
described above.
[0059] Energy may be applied together with an electrolyte solution,
which can be delivered, for example, by way of a channel running
through the long axis of the device (e.g., a working channel). The
solution can also be contained in a reservoir within the device and
delivered to the applicator region of the device in order to
facilitate energy transfer from the energy-emitting element to the
tissue. The electrolyte solution can be preheated to a selected
temperature and modified as necessary.
[0060] Generally, the energy conduit can be a wire, waveguide,
fiberoptic (or optical fiber), and the energy delivered can be
interstitial, monopolar, bipolar, or dipolar. To reduce the risk of
possible overheating and to carry away unwanted heat, a cooling
aluminum can be positioned in the device. For example, the
electrode or light guide can include a cooling lumen that is
contiguous with the source of cooling fluid or gas. If a gas or
air-cooled gap region is used, the tissue may be cooled, for
example, by air-conditioned or room air or other gas directed to
the tissue. The cooling liquid or gas may be applied continuously
or intermittently as required to maintain the temperature of the
tissue.
[0061] During treatment, the methods can be conducted under a
feedback control, which can be accomplished by visualization,
impedance, and ultrasound, with temperature measurement. One of
ordinary skill in the art would understand the common instruments
used for these feedback controls. If temperature measurement is
used, the device can either be external to the energy delivery
device or included within the energy delivery device. Temperature
measurement can be accomplished by the use of one or more thermal
sensors, such as infrared, thermistor, semiconductor temperature
sensor, non-contact infrared detectors, or fiber-optic temperature
sensors.
[0062] Similarly, one or more impedance sensors could be used for
feedback control if radio frequency is used. Current and voltage
are used to calculate impedance. The power, phase, amplitude,
wavelength, frequency, pulse configuration, and pulse width may be
computer controlled using feedback signals. If a laser is used, the
power applied, amplitude, pulse configuration, and duty cycle may
be regulated under feedback control through a temperature
sensor.
[0063] The methods of the present invention can provide a minor
reduction of nutrient absorption or a significant reduction of
nutrient absorption depending on the extent to which the small
intestine is treated. In certain circumstances, it may be desirable
to reduce the amount of nutrients and calories that are absorbed to
only a certain point and then reduce them further in subsequent
treatments if need be.
[0064] As noted, the extent of vasculature treated depends
generally on several factors, including the amount of the tissue
treated and the power, frequency, amplitude, pulse configuration,
and pulse width of the energy applied. If laser is used the power
can be in the range of about 1 to 100 Watts/cm.sup.2 (at least or
about 25, 30, 35, or 40 watts/cm.sup.2). The wavelength can affect
the method of the present invention by varying the efficiency of
the absorption into the target chromophore, which, in the present
methods, is blood contained in the vascular structure of the
intestinal wall and the vascular structure itself. The pulse
configuration can affect the method of the present invention by
applying the energy gradually or instantaneously with either an
abrupt or gradual reduction of energy. The pulse configuration can
be in the range of about 1 pps to about 1000 pps (e.g., at least or
about 5, 10, 12, 15, or 20 pps). The pulse width can be in the
range of about 1 microsecond to about 1 sec (e.g., at least or
about 0.1, 0.5, 1.0, 1.5, or 2.0 sec). Intermediate ranges of the
figures just described are also useful within the methods of the
present invention. For example, power in the range of 10-25
watts/cm.sup.2 can be used, as can a pulse width of 0.01-100
ms.
[0065] The applicators used for the procedures described herein can
vary in design depending on the type of energy used and the
percentage of target tissue expected to be treated. A simple laser
fiber, housed with a lens on or near the distal tip of the
applicator, can be inserted into the lumen of the small intestine
with no direct visualization (e.g., under fluoroscopic image
control). The fiber would be advanced through the intestine or a
portion thereof (e.g., a length of about 2-6 inches) while
treatment is accomplished. The laser fiber and lens can be a part
of (e.g., affixed within) a centering ring or ball, which provides
greater control of the position of the fiber during treatment. With
these applicators, little or no expansion of the intestinal wall
would be created, thus allowing for treatment of patients in which
a low percentage of tissue (e.g., about 5-35% of the intestine) is
to be treated.
[0066] It may also be advantageous to maintain a substantially
constant and consistent amount of pressure across an area to be
treated with an applicator. To maintain consistent application of
energy in the treatment area, a gas or an inflatable object may be
placed in the abdominal cavity to apply counter pressure to the
applicator.
[0067] As noted, the present devices include one or more tissue
expanders, which can be variously configured. For example, the
expander can be shaped symmetrically, as a ring, or asymmetrically,
for example as an irregularly-shaped cavity, either of which can be
expanded to generate a structure that exerts pressure against the
intestinal lumen (e.g., through mechanical expansion or by
inflation; a "balloon"). The expander can be used to expose more of
the tissue of the intestinal wall to the energy-emitting element. A
device with an expanded balloon (e.g., expanded to about the
diameter of the intestinal lumen or slightly more) provides not
only additional access to the blood vessels vascularizing the
intestinal tissue but also "unfolds" the normal folds of the
intestinal wall, thereby exposing a larger area of vessels to be
treated and increasing the total amount of vasculature treated.
Because of the shape of the small intestine and the pliability of
the wall of the small intestine, this object may also provide
access to areas of the small intestine that may not otherwise be
contacted by the energy.
[0068] The tissue expander in the present devices can be made from
any of the materials used for the balloon-portion of devices for
other minimally invasive procedures. These materials can withstand
high pressure and yet have thin walls, high strength, and a small
profile. The tissue expander can assume a wide range of diameters,
lengths, and shapes, and can be custom formed if necessary for
optimum expansion of a portion of the intestinal lumen. The
material can be a high-pressure, non-elastic material or a lower
pressure elastomeric balloon made, for example, of latex or
silicone. For example, a balloon tissue expander can be formed from
polyvinyl chloride, crosslinked polyethylene or another polyolefin,
nylon, polyurethane, or PET (polyethylene terephthalate).
[0069] Alternatively, a vacuum may be used to draw the intestinal
wall nearer to the energy-emitting element, thereby facilitating
access to portions of the intestine that are harder to reach. The
vacuum may be applied through a working channel of the device, as
illustrated in the accompanying drawings. In such an instance, the
device may contain a gasket that allows the vacuum to be in contact
with the tissue and to hold the intestinal wall in place as an
energy-emitting element (e.g., the terminus of one or more optical
fibers) is placed near or against the intestinal wall to apply the
energy. A vacuum can also be applied independently of the present
device. For example, an endoscope may include a port through which
vacuum or negative pressure can be applied.
[0070] The present methods can be combined with other therapies,
such as dietary counseling, hypnosis, behavior modification, and
pharmacological intervention.
[0071] The components of the devices described herein can be
attached or assembled through standard electromechanical couplings
known in the art or readily understandable by one of ordinary skill
in the art.
[0072] A number of embodiments of the invention have been
described. Nevertheless, it will be understood that various
modifications may be made without departing from the spirit and
scope of the invention. Accordingly, other embodiments are within
the scope of the following claims.
* * * * *